In general, birds that winter in the Mediterranean and therefore have a shorter distance to cover arrive earlier than those returning from far-away tropical Africa.

The weather can delay the migrants’ schedule by a few days, but it will not significantly alter it. Climate change, however, has resulted in certain species arriving several days earlier than they did thirty years ago.

“One swallow does not make a summer.” As the saying implies, not all individuals of a particular species return at once. The first Barn Swallows are usually sighted around 20 March, the main group in the first half of April, and the last individuals not until the end of May. In many species, the males arrive several days before the females in order to secure a good nesting site.